Note: if you change between WI-FI and LAN your tv will have different Device Ids
Make sure that the url works by testing it in the browser. If it downloads the m3u file.
If you have problems getting your url to work.
Try to upload your m3u file insted.
How: Open your url in a browser. Save it to your harddrive. Enter your device id here and select the file. Press upload.
Enter the Device ID for your Tv or mobile
Tizen version can be found in your samsung tv app store